标题： 冷原子云发出的相干光脉冲 显示英文标题

标题： Coherent flash of light emitted by a cold atomic cloud

摘要： 当一束共振激光被突然关闭时，会在一个光学厚度大的冷原子云中产生向前方向的相干光脉冲。 这种瞬态现象是由于原子散射体的高度共振特性而被观察到的。 我们定量分析了其时空特性，并与理论预测有很好的一致性。 基于互补实验，无需干涉测量工具即可重建相干场的相位。 显示英文摘要

摘要： When a resonant laser sent on an optically thick cold atomic cloud is abruptly switched off, a coherent flash of light is emitted in the forward direction. This transient phenomenon is observed due to the highly resonant character of the atomic scatterers. We analyze quantitatively its spatio-temporal properties and show very good agreement with theoretical predictions. Based on complementary experiments, the phase of the coherent field is reconstructed without interferometric tools.